U.S. patent application number 16/651973 was filed with the patent office on 2020-08-13 for optical apparatus, optical system, and method for measuring an amount of strain of an object.
The applicant listed for this patent is BOE TECHNOLOGY GROUP CO., LTD., HEFEI BOE DISPLAY TECHNOLOGY CO., LTD.. Invention is credited to Ke DAI, Peng JIANG, Zhonghou WU, Haipeng YANG, Chunxu ZHANG, Qiong ZHANG, Yuntian ZHANG.
Application Number | 20200256667 16/651973 |
Document ID | / |
Family ID | 69643900 |
Filed Date | 2020-08-13 |
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United States Patent
Application |
20200256667 |
Kind Code |
A1 |
ZHANG; Yuntian ; et
al. |
August 13, 2020 |
OPTICAL APPARATUS, OPTICAL SYSTEM, AND METHOD FOR MEASURING AN
AMOUNT OF STRAIN OF AN OBJECT
Abstract
An optical apparatus includes a coherent light source; a
transmission assembly configured to receive light emitted by the
coherent light source, split the light into object light and
reference light so that the object light and the reference light
travel along different paths receive object light reflected by an
object to be measured, and combine the object light reflected by
the object to be measured and the reference light; and a
photosensitive camera disposed at an output of the transmission
assembly, and configured to receive combined light and process the
combined light to record light intensity information capable of
characterizing a spatial position of a surface of the object to be
measured.
Inventors: |
ZHANG; Yuntian; (Beijing,
CN) ; ZHANG; Chunxu; (Beijing, CN) ; WU;
Zhonghou; (Beijing, CN) ; ZHANG; Qiong;
(Beijing, CN) ; DAI; Ke; (Beijing, CN) ;
YANG; Haipeng; (Beijing, CN) ; JIANG; Peng;
(Beijing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HEFEI BOE DISPLAY TECHNOLOGY CO., LTD.
BOE TECHNOLOGY GROUP CO., LTD. |
Hefei, Anhui
Beijing |
|
CN
CN |
|
|
Family ID: |
69643900 |
Appl. No.: |
16/651973 |
Filed: |
August 22, 2019 |
PCT Filed: |
August 22, 2019 |
PCT NO: |
PCT/CN2019/101968 |
371 Date: |
March 27, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01B 11/168 20130101;
G01B 11/161 20130101 |
International
Class: |
G01B 11/16 20060101
G01B011/16 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 28, 2018 |
CN |
201810990791.5 |
Claims
1. An optical apparatus, comprising: a coherent light source; a
transmission assembly configured to receive light emitted by the
coherent light source, split the light into object light and
reference light so that the object light and the reference light
travel along different paths, receive object light reflected by an
object to be measured, and combine the object light reflected by
the object to be measured and the reference light; and a
photosensitive camera disposed at an output of the transmission
assembly and configured to receive combined light and process the
combined light to record light intensity information capable of
characterizing a spatial position of a surface of the object to be
measured.
2. The optical apparatus according to claim 1, wherein the
photosensitive camera comprises: a micro-polarizer array configured
to cause interference between the object light reflected by the
object to be measured and the reference light in the combined light
to generate interference fringes; and an image sensor configured to
record light intensity information of the interference fringes.
3. The optical apparatus according to claim 2, wherein the
micro-polarizer array comprises a plurality of micro-polarizers
arranged in an array, and the plurality of micro-polarizers are
divided into a plurality of repeating units; each of the plurality
of repeating units comprises at least four adjacent
micro-polarizers, all micro-polarizers comprised in each repeating
unit are arranged in N rows and M columns, and polarization
directions of the micro-polarizers in the repeating unit are
different, wherein N is greater than or equal to 2, and M is
greater than or equal to 2; and the image sensor comprises a
plurality of photosensitive elements disposed in one-to-one
correspondence with the plurality of micro-polarizers.
4. The optical apparatus according to claim 3, wherein the
repeating unit comprises four micro-polarizers, and polarization
directions of the four micro-polarizers are 0.degree., 45.degree.,
90.degree., and 135.degree..
5. The optical apparatus according to claim 3, wherein the
plurality of micro-polarizers in the micro-polarizer array are
attached to the image sensor through a photosensitive adhesive; or
the image sensor comprises a wafer in which the plurality of
photosensitive elements are disposed, and the micro-polarizer array
is formed on the wafer.
6. The optical apparatus according to claim 1, wherein the
transmission assembly comprises: a light-splitting component
configured to split the light emitted by the coherent light source
into the object light and the reference light, polarization
directions of which are perpendicular to each other; an object
light transmission component configured to receive the object
light, direct the object light toward the object to be measured,
and reflect the object light reflected by the object to be
measured; and a light-combining component configured to receive
object light reflected by the object light transmission component
and the reference light, and combine the object light reflected by
the object light transmission component and the reference
light.
7. The optical apparatus according to claim 6, wherein the
transmission assembly further comprises: a reflecting component
configured to reflect the reference light output from the
light-splitting component to the light-combining component; and a
first light-modulating component disposed at an output of the
light-combining component, and configured to convert light combined
by the light-combining component from linearly polarized light to
circularly polarized light.
8. The optical apparatus according to claim 6, wherein the
light-splitting component comprises a first polarization beam
splitter prism; and the light-combining component composes a second
polarization beam splitter prism.
9. The optical apparatus according to claim 6, wherein the object
light transmission component comprises a transflective beam
splitter prism.
10. The optical apparatus according to claim 7, wherein the
reflecting component comprises a reflecting mirror; and the first
light-modulating component comprises a quarter wave plate.
11. The optical apparatus according to claim 7, further comprising:
at least one collimated beam expander disposed between the coherent
light source and the light-splitting component, wherein each
collimated beam expander comprises at least two lenses, and focal
lengths of the at least two lenses are different.
12. The optical apparatus according to claim 1 further comprising:
a second light-modulating component disposed between the coherent
light source and a collimated beam expander that is most proximate
to the coherent light source in the at least one collimated beam
expander, wherein the second light-modulating component is
configured to modulate a linear polarization angle of the light
emitted by the coherent light source.
13. The optical apparatus according to claim 12, wherein the second
light-modulating component comprises a half wave plate.
14. An optical system, comprising: the optical apparatus according
to claim 1; and a processor configured to calculate phase
information of the object light reflected by the object to be
measured according to light intensity information recorded by the
photosensitive camera in the optical apparatus, and calculate an
amount of strain of the object to be measured according to a change
between phase information before the object to be measured is
deformed and phase information after the object to be measured is
deformed.
15. A method for measuring an amount of strain of an object,
applied to the optical system according to claim 14, the method
comprising: calculating the phase information of the object light
reflected by the object to be measured according to the light
intensity information recorded by the optical apparatus in the
optical system; and calculating the amount of strain of the object
to be measured according to a change between the phase information
before the object to be measured is deformed and the phase
information after the object to be measured is deformed.
16. The method for measuring the amount of strain of the object
according to claim 15, wherein the optical apparatus comprises a
photosensitive camera, and the photosensitive camera comprises a
micro-polarizer array and an image sensor; the micro-polarizer
array comprises a plurality of micro-polarizers, each repeating
unit comprises at least four adjacent micro-polarizers, all
micro-polarizers comprised in each repeating unit are arranged in N
rows and M columns, and polarization directions of all the
micro-polarizers comprised in the repeating unit are different,
wherein N is greater than or equal to 2, M is greater than or equal
to 2; and the image sensor comprises a plurality of photosensitive
elements disposed in one-to-one correspondence with the plurality
of micro-polarizers; calculating the phase information of the
object light reflected by the object to be measured according to
the light intensity information recorded by the optical apparatus
in the optical system, comprises: obtaining a relational expression
between light intensity information I recorded by each
photosensitive element and phase information .omega. of object
light received by a corresponding repeating unit according to a
following formula (1): I=1/2[I.sub.s+I.sub.r+2 {square root over
(I.sub.sI.sub.t)} cos(.omega.+2.alpha.)] (1), (1) wherein .alpha.
represents a polarization angle of a micro-polarizer corresponding
to the photosensitive element, I.sub.s represents a light intensity
of object light received by the photosensitive element, and I.sub.r
represents a light intensity of reference light received by the
photosensitive element; and calculating the phase information
.omega. of the object light received by the corresponding repeating
unit according to the relational expression between the light
intensity information I recorded by the photosensitive element and
the phase information .omega. of the object light received by the
corresponding repeating unit, and the light intensity information I
recorded by the photosensitive element, wherein phase information
.omega. of object light received by all repeating units constitutes
the phase information of the object light reflected by the object
to be measured.
17. The method for measuring the amount of strain of the object
according to claim 16, wherein in a case where each repeating unit
comprises four micro-polarizers, and polarization angles of the
four micro-polarizers are 0.degree., 45.degree., 90.degree., and
135.degree., relational expressions between light intensity
information I.sub.1, I.sub.2, I.sub.3, and I.sub.4 recorded by
respective photosensitive elements corresponding to respective
micro-polarizers in the repeating unit and the phase information
.omega. of the object light received by the repeating unit are
respectively: I.sub.1=1/2[I.sub.s+I.sub.r+2 {square root over
(I.sub.sI.sub.r)} cos(.omega.)] (2); (2)
I.sub.2=1/2[I.sub.s+I.sub.r-2 {square root over (I.sub.sI.sub.r)}
sin(.omega.)] (3); (3) I.sub.3=1/2[I.sub.s+I.sub.r-2 {square root
over (I.sub.sI.sub.r)} cos(.omega.)] (4); (4)
I.sub.r=1/2[I.sub.s+I.sub.r+2 {square root over (I.sub.sI.sub.r)}
sin(.omega.)] (5); and (5) according to relational expressions (2)
to (5), and the light intensity information I.sub.1, l.sub.2,
I.sub.3, and I.sub.4 recorded by the respective photosensitive
elements corresponding to the respective micro-polarizers in the
repeating unit, the phase information of the object light received
by the corresponding repeating unit is calculated to be: .omega. =
arctan ( I 4 - I 2 I 1 - I 3 ) . ( 6 ) ##EQU00007##
18. The method for measuring the amount of strain of the object
according to claim 16, wherein calculating the amount of strain of
the object to be measured according to a change between the phase
information before the object to be measured is deformed and the
phase information after the object to be measured is deformed,
comprises: obtaining phase information .omega..sub.2(i, j) of
object light received by respective photosensitive elements
corresponding to respective micro-polarizers in a repeating unit
that is in an i-th row and in a j-th column before the object to be
measured is deformed, and phase information .omega..sub.1(i, j) of
object light received by the respective photosensitive elements
corresponding to the respective micro-polarizers in the repeating
unit that is in the i-th row and in the j-th column after the
object to be measured is deformed; calculating an amount of strain
in an x direction of the surface of the object to be measured that
is photographed by the respective photosensitive elements
corresponding to the respective micro-polarizers in the repeating
unit that is in the i-th row and in the j-th column according to a
following formula (7), .omega..sub.1(i, j) and .omega..sub.2(i, j):
x = .omega. 1 ( i , j ) - .omega. 2 ( i , j ) .DELTA. x ; ( 7 )
##EQU00008## and calculating an amount of strain in a y direction
of the surface of the object to be measured that is photographed by
the respective photosensitive elements corresponding to the
respective micro-polarizers in the repeating unit that is in the
i-th row and in the j-th column according to a following formula
(8), .omega..sub.1(i, j) and .omega..sub.2(i, j): y = .omega. 1 ( i
, j ) - .omega. 2 ( i , j ) .DELTA. y , ( 8 ) ##EQU00009## wherein
i and j are both positive integers, the x direction and the y
direction are perpendicular to each other, and .DELTA.x and
.DELTA.y are respectively actual sizes of a region of the object to
be measured corresponding to the photosensitive elements in the x
direction and in the y direction.
19. A non-transitory computer-readable storage medium storing
computer program instructions that, when run by a processor, cause
the processor to perform one or more steps of the method for
measuring the amount of strain of the object according to claim
15.
20. An electronic device, comprising a processor and a memory,
wherein the memory stores computer program instructions suitable
for being executed by the processor, and when the computer program
instructions are run by the processor, the processor performs one
or more steps of the method for measuring the amount of strain of
the object according to claim 15.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a national phase entry under 35 USC 371
of International Patent Application No. PCT/CN2019/101968 filed on
Aug. 22, 2019, which claims priority to Chinese Patent Application
No. 201810990791.5, filed with the Chinese Patent Office on Aug.
28, 2018, which are incorporated herein by reference in their
entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to the technical field of
strain measurement of an object, and in particular, to an optical
apparatus, an optical system, and a method for measuring an amount
of strain of an object.
BACKGROUND
[0003] A strain reflects deformation condition of a structure after
the structure is subjected to stress. An application of a strain
measurement is important in a case where materials having various
types of structures are in a complex working environment such as a
high-temperature working environment, a high-pressure working
environment or a high-speed working environment. Results of the
strain measurement may reflect mechanical condition of a structural
component that results from structural characteristics, dynamic
loads and environmental loads in a working process. Therefore,
failures of materials of some parts where the stress is
concentrated (such as a main wing of a jet airplane and a propeller
of a turboprop aircraft) due to long time cycle loads may be
prevented, and an overall devastating damage to the system may be
further prevented.
SUMMARY
[0004] In one aspect, an optical apparatus is provided. The optical
apparatus includes: a coherent light source; a transmission
assembly configured to receive light emitted by the coherent light
source, split the light into object light and reference light so
that the object light and the reference light travel along
different paths, receive object light reflected by an object to be
measured, and combine the object light reflected by the object to
be measured and the reference light; and a photosensitive camera
disposed at an output of the transmission assembly and configured
to receive combined light and process the combined light to record
light intensity information capable of characterizing a spatial
position of a surface of the object to be measured.
[0005] In some embodiments, the photosensitive camera includes: a
micro-polarizer array configured to cause interference between the
object light reflected by the object to be measured and the
reference light in the combined light to generate interference
fringes; and an image sensor configured to record light intensity
information of the interference fringes.
[0006] In some embodiments, the micro-polarizer array includes a
plurality of micro-polarizers arranged in an array. The plurality
of micro-polarizers are divided into a plurality of repeating
units. Each of the plurality of repeating units includes at least
four adjacent micro-polarizers. All micro-polarizers included in
each repeating unit are arranged in N rows and M columns, and
polarization directions of the micro-polarizers in the repeating
unit are different. N is greater than or equal to 2, and M is
greater than or equal to 2. The image sensor includes a plurality
of photosensitive elements disposed in one-to-one correspondence
with the plurality of micro-polarizers.
[0007] In some embodiments, the repeating unit includes four
micro-polarizers, and polarization directions of the four
micro-polarizers are 0.degree., 45.degree., 90.degree., and
135.degree..
[0008] In some embodiments, the plurality of micro-polarizers in
the micro-polarizer array are attached to the image sensor through
a photosensitive adhesive. Or, the image sensor includes a wafer in
which the plurality of photosensitive elements are disposed, and
the micro-polarizer array is formed on the wafer.
[0009] In some embodiments, the transmission assembly includes: a
light-splitting component configured to split the light emitted by
the coherent light source into object light and reference light,
polarization directions of which are perpendicular to each other;
an object light transmission component configured to receive the
object light, direct the object light toward the object to be
measured, and reflect the object light reflected by the object to
be measured; and a light-combining component configured to receive
object light reflected by the object light transmission component
and the reference light, and combine the object light reflected by
the object light transmission component and the reference
light.
[0010] In some embodiments, the transmission assembly further
includes: a reflecting component configured to reflect the
reference light output from the light-splitting component to the
light-combining component; and a first light-modulating component
disposed at an output of the light-combining component, and
configured to convert light combined by the light-combining
component from linearly polarized light to circularly polarized
light.
[0011] In some embodiments, the light-splitting component includes
a first polarization beam splitter prism. The light-combining
component includes a second polarization beam splitter prism.
[0012] In some embodiments, the object light transmission component
includes a transflective beam splitter prism.
[0013] In some embodiments, the reflective component includes a
reflecting mirror. The first light-modulating component includes a
quarter wave plate.
[0014] In some embodiments, the optical apparatus further includes:
at least one collimated beam expander disposed between the coherent
light source and the light-splitting component. Each collimated
beam expander includes at least two lenses, and focal lengths of
the at least two lenses are different.
[0015] In some embodiments, the optical apparatus further includes:
a second light-modulating component disposed between the coherent
light source and a collimated beam expander that is most proximate
to the coherent light source in the at least one collimated beam
expander. The second light-modulating component is configured to
modulate a linear polarization angle of the light emitted by the
coherent light source.
[0016] In some embodiments, the second light-modulating component
includes a half wave plate.
[0017] In another aspect, an optical system is provided. The
optical system includes: the optical apparatus according to any of
the above embodiments; a processor configured to calculate phase
information of the object light reflected by the object to be
measured according to light intensity information recorded by the
photosensitive camera in the optical apparatus, and calculate an
amount of strain of the object to be measured according to a change
between the phase information before the object to be measured is
deformed and the phase information after the object to be measured
is deformed.
[0018] In yet another aspect, a method for measuring an amount of
strain of an object applied to the optical system in any of the
above embodiments is provided. The method includes: calculating the
phase information of the object light reflected by the object to be
measured according to the light intensity information recorded by
the optical apparatus in the optical system; and calculating the
amount of strain of the object to be measured according to a change
between the phase information before the object to be measured is
deformed and the phase information after the object to be measured
is deformed.
[0019] In some embodiments, the optical apparatus includes a
photosensitive camera including a micro-polarizer array and an
image sensor. The micro-polarizer array includes a plurality of
micro-polarizers, each repeating unit includes at least four
adjacent micro-polarizers. All micro-polarizers included in each
repeating unit are arranged in N rows and M columns, and
polarization directions of all the micro-polarizers included in the
repeating unit are different. N is greater than or equal to 2, and
M is greater than or equal to 2. The image sensor includes a
plurality of photosensitive elements disposed in one-to-one
correspondence with the plurality of micro-polarizers.
[0020] The step of calculating the phase information of the object
light reflected by the object to be measured according to the light
intensity information recorded by the optical apparatus in the
optical system includes:
[0021] obtaining a relational expression between light intensity
information I recorded by each photosensitive element and phase
information .omega. of object light received by a corresponding
repeating unit according to a following formula (1):
I=1/2[I.sub.s+I.sub.r+2 {square root over (I.sub.sI.sub.r)} cos
(.omega.+2.alpha.)] (1)
[0022] wherein .alpha. represents a polarization angle of a
micro-polarizer corresponding to the photosensitive element,
I.sub.s represents a light intensity of object light received by
the photosensitive element, and l.sub.r represents a light
intensity of reference light received by the photosensitive
element; and
[0023] calculating the phase information .omega. of the object
light received by the corresponding repeating unit according to the
relational expression between the light intensity information I
recorded by the photosensitive element and the phase information
.omega. of the object light received by the corresponding repeating
unit, and the light intensity information I recorded by the
photosensitive element. Phase information .omega. of object light
received by all repeating units constitutes the phase information
of the object light reflected by the object to be measured.
[0024] In some embodiments, in a case where each repeating unit
includes four micro-polarizers, and polarization angles of the four
micro-polarizers are respectively 0.degree., 45.degree.,
90.degree., and 135.degree..
[0025] relational expressions between light intensity information
I.sub.1, I.sub.2, I.sub.3, and I.sub.4 recorded by respective
photosensitive elements corresponding to respective
micro-polarizers in the repeating unit and the phase information w
of the object light received by the repeating unit are
respectively:
I.sub.1=1/2[I.sub.s+I.sub.r+2 {square root over (I.sub.sI.sub.r)}
cos (.omega.)] (2);
I.sub.2=1/2[I.sub.s+I.sub.r-2 {square root over (I.sub.sI.sub.r)}
sin (.omega.)] (3);
I.sub.3=1/2[I.sub.s+I.sub.r-2 {square root over (I.sub.sI.sub.r)}
cos (.omega.)] (4);
I.sub.4=1/2[I.sub.s+I.sub.r+2 {square root over (I.sub.sI.sub.r)}
sin(.omega.)] (5); and
[0026] according to relational expressions (2) to (5), and the
light intensity information I.sub.1, I.sub.2, I.sub.3, and I.sub.4
recorded by the respective photosensitive elements corresponding to
the respective micro-polarizers in the repeating unit, the phase
information of the object light received by the corresponding
repeating unit is calculated to be:
.omega. = arctan ( I 4 - I 2 I 1 - I 3 ) . ( 6 ) ##EQU00001##
[0027] In some embodiments, the step of calculating the amount of
strain of the object to be measured according to a change between
the phase information before the object to be measured is deformed
and the phase information after the object to be measured is
deformed, includes:
[0028] obtaining phase information .omega..sub.2(i, j) of object
light received by respective photosensitive elements corresponding
to respective micro-polarizers in a repeating unit that is in an
i-th row and in a j-th column before the object to be measured is
deformed, and phase information .omega..sub.1(i, j) of object light
received by the respective photosensitive elements corresponding to
the respective micro-polarizers in the repeating unit that is in
the i-th row and in the j-th column after the object to be measured
is deformed;
[0029] calculating an amount of strain in an x direction of the
surface of the object to be measured that is photographed by the
respective photosensitive elements corresponding to the respective
micro-polarizers in the repeating unit that is in the i-th row and
in the j-th column according to a following formula (7),
.omega..sub.1(i, j) and .omega..sub.2(i, j):
x = .omega. 1 ( i , j ) - .omega. 2 ( i , j ) .DELTA. x ; ( 7 )
##EQU00002##
and
[0030] calculating an amount of strain in a y direction of the
surface of the object to be measured that is photographed by the
respective photosensitive elements corresponding to the respective
micro-polarizers in the repeating unit that is in the i-th row and
in the j-th column according to a following formula (8),
.omega..sub.1(i, j) and .omega..sub.2(i, j):
y = .omega. 1 ( i , j ) - .omega. 2 ( i , j ) .DELTA. y , ( 8 )
##EQU00003##
[0031] wherein i and j are both positive integers, the x direction
and the y direction are perpendicular to each other, and .DELTA.x
and .DELTA.y are respectively actual sizes of a region of the
object to be measured corresponding to the photosensitive elements
in the x direction and in the y direction.
[0032] In yet another aspect, a non-transitory computer-readable
storage medium is provided. The non-transitory computer-readable
storage medium stores computer program instructions that, when run
by a processor, cause the processor to perform one or more steps of
the method for measuring the amount of strain of the object
according to any of the above embodiments.
[0033] In yet another aspect, an electronic device is provided. The
electronic device includes a processor and a memory. The memory
stores computer program instructions suitable for being executed by
the processor. When the computer program instructions are run by
the processor, the processor performs one or more steps of the
method for measuring the amount of strain of the object according
to any of the above embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] In order to describe technical solutions in embodiments of
the present disclosure more clearly, the accompanying drawings to
be used in the description of embodiments will be introduced
briefly. Obviously, the accompanying drawings to be described below
are merely some embodiments of the present disclosure, and a person
of ordinary skill in the art can obtain other drawings according to
these drawings.
[0035] FIG. 1 is a schematic diagram showing a structure of an
optical apparatus, according to some embodiments of the present
disclosure;
[0036] FIG. 2 is a schematic diagram of a micro-polarizer array,
according to some embodiments of the present disclosure;
[0037] FIG. 3 is a schematic diagram of an image sensor, according
to some embodiments of the present disclosure;
[0038] FIG. 4 is a schematic diagram showing a structure of another
optical apparatus, according to some embodiments of the present
disclosure;
[0039] FIG. 5 is a schematic diagram showing a structure of yet
another optical apparatus, according to some embodiments of the
present disclosure;
[0040] FIG. 6 is a schematic diagram showing a structure of yet
another optical apparatus, according to some embodiments of the
present disclosure;
[0041] FIG. 7 is a schematic diagram showing a structure of an
optical system, according to some embodiments of the present
disclosure;
[0042] FIG. 8 is a schematic flow diagram of a method for measuring
an amount of strain of an object, according to some embodiments of
the present disclosure;
[0043] FIG. 9 is a schematic diagram of fixing the micro-polarizer
array to the image sensor, according to some embodiments of the
present disclosure; and
[0044] FIG. 10 is a schematic diagram showing another structure of
fixing the micro-polarizer array to the image sensor, according to
some embodiments of the present disclosure.
DETAILED DESCRIPTION
[0045] Some embodiments of the present disclosure will be described
below in combination with the accompanying drawings. Obviously, the
described embodiments are merely some but not all of the
embodiments of the present disclosure. All other embodiments made
on the basis of the embodiments of the present disclosure by a
person of ordinary skill in the art shall be included in the
protection scope of the present disclosure.
[0046] Referring to FIG. 1, some embodiments of the present
disclosure provide an optical apparatus 1. The optical apparatus 1
includes a coherent light source 10, a transmission assembly 20,
and a photosensitive camera 30.
[0047] The coherent light source 10 is configured to emit light.
The transmission assembly 20 is configured to receive the light
emitted by the coherent light source, split the light into object
light and reference light so that the object light and the
reference light travel along different paths, receive object light
reflected by an object to be measured 2, and combine the object
light reflected by the object to be measured 2 and the reference
light. With this design, the transmission assembly 20 may be used
to cause the object light and the reference light in the light
emitted by the coherent light source 10 to travel along different
paths, and combine the reference light and the object light
reflected by the object to be measured 2 before the reference light
and the object light reflected by the object to be measured 2 reach
the photosensitive camera 30.
[0048] It will be noted that, in the process of measuring an amount
of strain of the object to be measured 2 by using the optical
apparatus 1, the object light split by the transmission assembly 20
may be directed toward the object to be measured 2. In this way,
the object light reflected by the object to be measured 2 that is
received by the transmission assembly 20 may carry spatial position
information of a surface of the object to be measured 2. The
reference light split by the transmission assembly 20 is not
directed toward the object to be measured 2. The reference light
may be combined with the object light reflected by the object to be
measured 2, so that the transmission assembly 20 may output the
combined light, and the combined light carries the spatial position
information of the surface of the object to be measured 2.
[0049] The photosensitive camera 30 is disposed at an output of the
transmission assembly 20. The photosensitive camera 30 is
configured to receive the combined light output by the transmission
assembly 20 and process the combined light to record light
intensity information capable of characterizing the spatial
position of the surface of the object to be measured 2. With this
design, the photosensitive camera 30 may record light intensity
information characterizing a spatial position of the surface of the
object to be measured 2 before the object to be measured 2 is
deformed and light intensity information characterizing a spatial
position of the surface of the object to be measured 2 after the
object to be measured 2 is deformed, and thus the amount of strain
of the object to be measured 2 may be obtained according to a
change between the two pieces of light intensity information.
Therefore, the optical apparatus 1 may detect a dynamic deformation
of the object to be measured 2 in real time. In addition, the
object to be measured 2 is only irradiated by the light and will
not be damaged.
[0050] For example, the object to be measured 2 includes a civil
bridge, an aircraft, a transportation vehicle, or the like. That
is, the optical apparatus 1 may be applied to real-time strain
detection and monitoring of the civil bridge, the aircraft, the
transportation vehicle, or the like.
[0051] In some embodiments, as shown in FIGS. 2 and 3, the
photosensitive camera 30 includes a micro-polarizer array 31 and an
image sensor 32. The micro-polarizer array 31 is configured to
cause interference between the object light and the reference light
in the combined light to generate interference fringes. The image
sensor 32 is configured to record light intensity information of
the interference fringes.
[0052] Here, it will be noted that, the object light in the
combined light is the object light reflected by the object to be
measured 2. Therefore, after phase-shift interference occurs
between the object light and the reference light in the combined
light through the micro-polarizer array 31, the light intensity
information of the generated interference fringes may characterize
the spatial position of the surface reflecting the object light of
the object to be measured 2. With this design, the photosensitive
camera 30 may record light intensity information of interference
fringes corresponding to the spatial position of the surface of the
object to be measured 2 before the object to be measured 2 is
deformed and light intensity information of interference fringes
corresponding to the spatial position of the surface of the object
to be measured 2 after the object to be measured 2 is deformed, and
thus the amount of strain of the object to be measured 2 may be
obtained according to the change between the two pieces of light
intensity information.
[0053] It will be noted that, the light emitted by the coherent
light source 10 is coherent light. Therefore, after the light
emitted by the coherent light source 10 reaches the object to be
measured 2 and the transmission assembly 20, the combined light
output by the transmission assembly 20 may interfere to generate
the interference fringes. In this way, by recording the light
intensity information of the interference fringes by the image
sensor 32, the spatial position information of the surface of the
object to be measured 2 may be obtained.
[0054] For example, the coherent light source 10 is a laser. The
laser may generate coherent light with a better coherence, which
may improve an interference effect of the coherent light and make
the light intensity information of the interference fringes
recorded by the image sensor 32 more accurate. As a result, the
amount of strain of the object to be measured 2 may be measured and
analyzed, and a more accurate measurement result may be
obtained.
[0055] In some embodiments, as shown in FIG. 2, the micro-polarizer
array 31 includes a plurality of micro-polarizers 311 arranged in
an array. For example, the micro-polarizer array 31 is a
micro-polarizer array based on metal nano-gratings. For example,
the micro-polarizer array 31 includes a base with a high light
transmittance and metal nano-gratings arranged on the base.
Directions in which the metal nano-gratings are arranged on the
base are not exactly the same. A grating composed of adjacent metal
nano-wires having a same arrangement direction is a
micro-polarizer, and a plurality of micro-polarizers form the
micro-polarizer array 31.
[0056] For example, as shown in FIG. 2, a length of each side of
each micro-polarizer 311 is L, and L is greater than or equal to 1
.mu.m, and is less than or equal to 15 .mu.m. For example, L is
between 1 .mu.m and 5 .mu.m, or L is between 6 .mu.m and 10 .mu.m,
or L is between 11 .mu.m and 15 .mu.m. For another example, L is 1
.mu.m, 5 .mu.m, 6 .mu.m, 7 .mu.m, 10 .mu.m, 11 .mu.m or 15
.mu.m.
[0057] The plurality of micro-polarizers 311 are divided into a
plurality of repeating units 312. Each of the plurality of
repeating units 312 includes at least four adjacent
micro-polarizers 311. All the micro-polarizers 311 included in each
repeating unit 312 are arranged in N rows and M columns, and
polarization directions of all the micro-polarizers included in the
repeating unit are different. N is greater than or equal to 2, and
M is greater than or equal to 2. For example, N is equal to 2, and
M is equal to 2. Or N is equal to 3, and M is equal to 4.
[0058] Here, it will be noted that, after the object light and the
reference light in the combined light emitted from the transmission
assembly 20 pass through each micro-polarizer 311, interference
occurs and interference fringes are generated.
[0059] By setting the polarization directions of the
micro-polarizers 311 in the micro-polarizer array 31, light
intensity information of interference fringes in different
polarization directions may be recorded by the image sensor. In
this way, phase information of the object light reflected by the
surface of the object to be measured 2 (the phase information of
the object light reflected by the surface of the object to be
measured 2 reflecting the spatial position information of the
surface of the object to be measured 2) may be obtained through
relevant calculation according to the light intensity information,
thereby obtaining the amount of strain of the object to be measured
2 according to phase information of object light reflected by the
surface of the object to be measured before the object to be
measured 2 is deformed and phase information of object light
reflected by the surface of the object to be measured after the
object to be measured 2 is deformed.
[0060] For example, as shown in FIG. 2, each repeating unit 312
includes four micro-polarizers 311, and polarization directions of
the four micro-polarizers 311 are 0.degree., 45.degree.,
90.degree., and 135.degree.. In this case, the four
micro-polarizers 311 included in the repeating unit 312 are
arranged in 2 rows and 2 columns. With this design, on one hand, an
entire micro-polarizer array is easily manufactured. On the other
hand, according to light intensity information of interference
fringes generated by the four micro-polarizers 311 in each
repeating unit 312, an amount of strain of a position corresponding
to the repeating unit may be measured and analyzed. Further, the
amounts of strain of positions corresponding to all the repeating
units on the object to be detected 2, i.e., the amount of strain of
the object to be measured 2, may be obtained.
[0061] On this basis, for example, as shown in FIG. 3, the image
sensor 32 includes a plurality of photosensitive elements 321, and
a region where each photosensitive element is located may also be
referred to as a pixel.
[0062] The plurality of photosensitive elements 321 are disposed in
one-to-one correspondence with the plurality of micro-polarizers
311. That is, each photosensitive element 321 of the plurality of
photosensitive elements 321 is disposed at a light exit side of a
micro-polarizer 311 corresponding to the photosensitive element
321. In this case, the plurality of photosensitive elements 321 are
also arranged in an array, and all photosensitive elements 321
corresponding to each repeating unit 312 in the plurality of
photosensitive elements 321 are also arranged in N rows and M
columns. After the interference fringes generated after the
combined light passes through each micro-polarizer 311 is
recognized by a corresponding photosensitive element 321, the
photosensitive element 321 may record light intensity information
of the interference fringes generated by the corresponding
micro-polarizer 311, thereby facilitating a measurement and an
analysis of the amount of strain of the object to be measured
2.
[0063] For example, the image sensor includes a charge coupled
device (CCD) image sensor, or a complementary metal-oxide
semiconductor (CMOS) image sensor.
[0064] There are a plurality of manners of fixing the
micro-polarizer array 31 to the image sensor 32. In some examples,
as shown in FIG. 9, the micro-polarizers 311 in the micro-polarizer
array 31 are attached to the image sensor 32 through a
photosensitive adhesive 70. In this way, the micro-polarizers in
the micro-polarizer array may be easily assembled with the image
sensor. That is, each micro-polarizer may be fixed on a
corresponding photosensitive element in the image sensor through
the photosensitive adhesive, which has advantages of reliable
connection and high stability. Furthermore, the photosensitive
adhesive does not easily affect a photosensitivity effect of the
photosensitive elements, such that the photosensitive elements may
still effectively record the light intensity information of the
interference fringes generated by the micro-polarizer array.
[0065] In addition, a stable and reliable integration of the
micro-polarizer array 31 and the image sensor 32 may also reduce a
sensitivity of the photosensitive camera 30 to environmental
changes. That is, the environmental changes do not easily affect
the light intensity information of the interference fringes
recorded by the image sensor. Therefore, the optical apparatus 1
may be applied to a complex measurement environment, a complex
stress-strain condition, and a limited strain measurement range,
and has a high robustness.
[0066] In some other examples, as shown in FIG. 10, the image
sensor 32 includes a wafer 322, and the micro-polarizer array 31 is
formed on the wafer 322. In this case, there are a plurality of
photosensitive elements in the wafer, and the micro-polarizer array
is directly manufactured on the wafer. In this way, each
micro-polarizer may be fixed on a corresponding photosensitive
element to form an integrated structure. For example, a thin film
is formed on the wafer through an evaporation process, and then the
thin film is etched through an etching process to obtain the
plurality of micro-polarizers to form a micro-polarizer array.
[0067] In this way, the micro-polarizer array 31 and the image
sensor 32 may be stably and reliably integrated, thereby reducing
the sensitivity of the photosensitive camera 30 to the
environmental changes. That is, the environmental changes do not
easily affect the light intensity information of the interference
fringes recorded by the image sensor. Therefore, the optical
apparatus 1 may be applied to the complex measurement environment,
the complex stress-strain condition, and the limited strain
measurement range, and has a high robustness.
[0068] In some embodiments, as shown in FIG. 4, the transmission
assembly 20 includes a light-splitting component 21, an object
light transmission component 22, and a light-combining component
23.
[0069] The light-splitting component 21 is configured to split the
light emitted by the coherent light source 10 into the reference
light and the object light, polarization directions of which are
perpendicular to each other. For example, as shown in FIG. 6, the
light-splitting component 21 is a first polarization beam splitter
prism 211. By using a property that a transmittance of P-polarized
light is 1 and a transmittance of S-polarized light is less than 1
when the light is incident at a Brewster angle, the first
polarization beam splitter prism 211 may make the P-polarized light
totally transmitted and make the S-polarized light reflected. In
this case, one of the P-polarized light and the S-polarized light
may be used as the object light and the other as the reference
light. For example, as shown in FIG. 6, the object light is the
P-polarized light and may pass through the first polarization beam
splitter prism 211. The reference light is the S-polarized light
and may be reflected by the first polarization beam splitter prism
211. Moreover, the polarization directions of the object light and
the reference light split by the first polarization beam splitter
prism 211 are perpendicular to each other.
[0070] The object light transmission component 22 is configured to
receive the object light output from the light-splitting component
21, direct the object light toward the object to be measured 2 and
reflect the object light reflected by the object to be measured 2.
For example, as shown in FIG. 6, the object light transmission
component 22 is a transflective beam splitter prism 221. At least a
part of object light incident on the transflective beam splitter
prism 221 is transmitted to be directed toward the object to be
measured 2. At least a part of object light reflected by the object
to be measured 2 to the transflective beam splitter prism 221 is
reflected to be directed toward the light-combining component 23.
It will be seen that, object light reflected by the object light
transmission component 22 to the light-combining component 23
actually carries the spatial position information of the surface of
the object to be measured 2. Here, it will be noted that, the phase
information of the object light reflected before the object to be
measured 2 is deformed is different from the phase information of
the object light reflected after the object to be measured 2 is
deformed, which is caused by a deformation of the surface
reflecting the object light of the object to be measured 2.
Therefore, it will be considered that the object light reflected by
the object to be measured 2 carries the spatial position
information of the surface of the object to be measured 2. On this
basis, the object light reflected by the object light transmission
component 22 to the light-combining component 23 also actually
carries the spatial position information of the surface of the
object to be measured 2.
[0071] The light-combining component 23 is configured to receive
the object light reflected by the object light transmission
component 22 and the reference light output from the
light-splitting component 21, and combine the object light
reflected by the object light transmission component 22 and the
reference light output from the light-splitting component 21. For
example, as shown in FIG. 6, the light-combining component 23 is a
second polarization beam splitter prism 231, and the second
polarization beam splitter prism 231 is the same as the first
polarization beam splitter prism 211. Therefore, it will be
understood that, compared with the first polarization beam splitter
prism 211, positions of an incident port and an exit port of the
second polarization beam splitter prism 231 are exactly opposite.
Therefore, the second polarization beam splitter prism 231 may
receive the object light reflected by the object light transmission
component 22 and the reference light output from the
light-splitting component 21, combine the object light reflected by
the object light transmission component 22 and the reference light
output from the light-splitting component 21, and output the
combined light.
[0072] On this basis, for example, as shown in FIG. 5, the
transmission assembly 20 further includes a reflecting component 24
and a first light-modulating component 25.
[0073] The reflecting component 24 is configured to reflect the
reference light. That is, the reflecting component 24 may reflect
the reference light output by the light-splitting component to the
light-combining component 23. For example, as shown in FIG. 6, the
reflecting component 24 is a reflecting mirror 241.
[0074] The first light-modulating component 25 is disposed at an
output of the light-combining component 23. The first
light-modulating component 25 is configured to convert the light
combined by the light-combining component 23 from linearly
polarized light to circularly polarized light. Here, it will be
noted that, the light emitted by the coherent light source is the
coherent light, and the coherent light is the linearly polarized
light. Therefore, the object light and reference light in the
combined light are also the linearly polarized light. The linearly
polarized reference light and the linearly polarized object light
may be converted into two circularly polarized light beams by the
first light-modulating component 25. For example, one light beam is
a left circularly polarized light beam, and the other light beam is
a right circularly polarized light beam. In this way, the two
circularly polarized light beams emitted from the first
light-modulating component 25 will interfere with each other after
passing through each micro-polarizer 311, and thus interference
fringes are generated. For example, as shown in FIG. 6, the first
light-modulating component 25 is a quarter wave plate 251.
[0075] In some embodiments, as shown in FIG. 6, the optical
apparatus 1 further includes at least one collimated beam expander
50 disposed between the coherent light source 10 and the
light-splitting component 21. Each collimated beam expander 50
includes at least two lenses 501, and focal lengths of the at least
two lenses 501 are different. In this way, a diameter of the light
emitted by the coherent light source 10 may be enlarged by the at
least one collimated beam expander, and a direction of the light
may be prevented from being deviated.
[0076] In some embodiments, as shown in FIG. 6, the optical
apparatus 1 further includes a second light-modulating component
60. The second light-modulating component 60 is disposed between
the coherent light source 10 and a collimated beam expander 50 that
is most proximate to the coherent light source in the at least one
collimated beam expander 50, and is configured to modulate a linear
polarization angle of the light emitted by the coherent light
source 10. For example, the second light-modulating component 60 is
a half wave plate 601. In this way, by rotating the half wave plate
601, a linear polarization angle of light passing through the half
wave plate 601 may be modulated, thereby modulating a luminance of
the light.
[0077] Some embodiments of the present disclosure further provide
an optical system 100. As shown in FIG. 7, the optical system 100
includes the optical apparatus 1 in any of the above embodiments,
and a processor 3. The processor 3 is configured to calculate the
phase information of the object light reflected by the object to be
measured 2 according to the light intensity information recorded by
the photosensitive camera 30 in the optical apparatus 1, and
calculate the amount of strain of the object to be measured 2
according to a change between the phase information before the
object to be measured 2 is deformed and the phase information after
the object to be measured 2 is deformed.
[0078] The processor 3 may be a central processing unit (CPU), or
any other general-purpose processor, a digital signal processor
(DSP), an application specific integrated circuit (ASIC), a field
programmable gate array (FPGA), or any other programmable logic
device, a discrete component gate circuit or a transistor logic
device, a discrete hardware component or the like. The
general-purpose processor may be a micro-processor, or any
conventional processor.
[0079] In the embodiments, by providing the processor 3, the light
intensity information recorded by the photosensitive camera 30 in
the optical apparatus 1 may be analyzed and calculated to obtain
the phase information of the object light reflected by the surface
of the object to be measured 2. The phase information of the object
light reflected by the surface of the object to be measured 2 may
reflect the spatial position information of the surface of the
object to be measured 2. Therefore, the processor 3 may obtain the
amount of strain of the object to be measured 2 according to the
phase information before the object to be measured 2 is deformed
and the phase information after the object to be measured 2 is
deformed.
[0080] For example, in a case where a main wing of an airplane is
measured by using the optical system, the optical apparatus of the
optical system may be installed on a main body of the airplane, so
that the object light output by the optical apparatus may be
radiated onto the main wing of the airplane, and the optical
apparatus may receive object light reflected by the main wing. In
this way, an amount of strain of the main wing of the airplane may
be measured and analyzed by using the optical system. In this case,
the processor connected to the optical apparatus in the optical
system may be installed inside the airplane or outside the
airplane. The processor may be connected to the optical apparatus
in a wireless communication manner or in a wired communication
manner, as long as the processor is capable of obtaining the light
intensity information recorded by the optical apparatus. In
addition, the processor may also be integrated into a control
system of the airplane.
[0081] Some embodiments of the present disclosure further provide a
method for measuring an amount of strain of an object, which is
applied to the optical system in any of the above embodiments. As
shown in FIG. 8, the method includes: calculating the phase
information of the object light reflected by the object to be
measured according to the light intensity information recorded by
the optical apparatus in the optical system; and calculating the
amount of strain of the object to be measured according to the
change between the phase information before the object to be
measured is deformed and the phase information after the object to
be measured is deformed.
[0082] In the embodiments, by analyzing and calculating the light
intensity information recorded by the optical apparatus in the
optical system, the phase information of the object light reflected
by the surface of the object to be measured may be obtained. The
phase information of the object light reflected by the surface of
the object to be measured 2 may reflect the spatial position
information of the surface of the object to be measured 2.
Therefore, the amount of strain of the object to be measured 2 may
be obtained through calculation and analysis according to the phase
information before the object to be measured 2 is deformed and the
phase information after the object to be measured 2 is
deformed.
[0083] In some embodiments, the optical apparatus includes a
photosensitive camera, and the photosensitive camera includes a
micro-polarizer array and an image sensor. The micro-polarizer
array includes a plurality of micro-polarizers, and each repeating
unit includes at least four adjacent micro-polarizers. All the
micro-polarizers included in the repeating unit are arranged in N
rows and M columns, and polarization directions of all the
micro-polarizers included in the repeating unit are different. N is
greater than or equal to 2, and M is greater than or equal to 2.
The image sensor includes a plurality of photosensitive elements,
and the plurality of photosensitive elements are disposed in
one-to-one correspondence with the plurality of
micro-polarizers.
[0084] The step of calculating the phase information of the object
light reflected by the object to be measured according to the light
intensity information recorded by the optical apparatus in the
optical system includes:
[0085] obtaining a relational expression between light intensity
information I recorded by each photosensitive element and phase
information .omega. received by a corresponding repeating unit
according to a following formula (1):
I=1/2[I.sub.s+I.sub.r+2 {square root over (I.sub.sI.sub.r)}
cos(.omega.+2.alpha.)] (1).
[0086] where .alpha. represents a polarization angle of a
micro-polarizer corresponding to the photosensitive element,
I.sub.s represents a light intensity of object light received by
the photosensitive element, and I.sub.r represents a light
intensity of reference light received by the photosensitive
element; and
[0087] calculating the phase information .omega. received by the
corresponding repeating unit according to the relational expression
between the light intensity information I recorded by the
photosensitive element and the phase information .omega. of the
object light received by the corresponding repeating unit, and the
light intensity information I recorded by the photosensitive
element. Phase information .omega. of the object light received by
all the repeating units constitutes the phase information of the
object light reflected by the object to be measured.
[0088] It will be noted that, in formula (1), the polarization
angle .alpha. of the micro-polarizer corresponding to the
photosensitive element is a known value. Since the polarization
directions (i.e., the polarization angles .alpha.) of the at least
four micro-polarizers included in each repeating unit are not the
same, at least four different relational expressions may be
obtained based on formula (1). Operations are performed by using
the obtained at least four different relational expressions, and
then I.sub.s and I.sub.r in the expressions may be canceled out,
thereby calculating the phase information .omega. of the object
light reflected by the object to be measured that is received by
the corresponding repeating unit.
[0089] As for each repeating unit, by providing at least four
micro-polarizers with different polarization directions, images of
interference fringes corresponding to respective polarization
components may be obtained, thereby obtaining the amount of strain
of the object to be measured more easily. For example, each
repeating unit includes four micro-polarizers, and polarization
angles of the four micro-polarizers are 0.degree., 45.degree.,
90.degree., and 135.degree.. Or, each repeating unit includes six
micro-polarizers, and polarization angles of the six
micro-polarizers are 0.degree., 30.degree., 45.degree., 90.degree.,
120.degree., and 135.degree..
[0090] Each repeating unit includes four micro-polarizers, and the
polarization angles of the four micro-polarizers are 0.degree.,
45.degree., 90.degree., and 135.degree..
[0091] In this case, relational expressions between light intensity
information I.sub.1, I.sub.2, I.sub.3, and I.sub.4 recorded by
respective photosensitive elements corresponding to the four
micro-polarizers in the repeating unit and the phase information
.omega. of the object light received by the repeating unit are
respectively:
I.sub.1=1/2[I.sub.s+I.sub.r+2 {square root over (I.sub.sI.sub.r)}
cos(.omega.)] (2);
I.sub.2=1/2[I.sub.s+I.sub.r-2 {square root over (I.sub.sI.sub.r)}
sin(.omega.)] (3);
I.sub.3=1/2[I.sub.s+I.sub.r-2 {square root over (I.sub.sI.sub.r)}
cos(.omega.)] (4);
I.sub.4=1/2[I.sub.s+I.sub.r+2 {square root over (I.sub.sI.sub.r)}
sin(.omega.)] (5);
[0092] According to relational expressions (2) to (5), and the
light intensity information I.sub.1, I.sub.2, I.sub.3, and I.sub.4
recorded by the respective photosensitive elements corresponding to
respective micro-polarizers in the repeating unit, the phase
information of the object light received by the corresponding
repeating unit is calculated to be:
.omega. = arctan ( I 4 - I 2 I 1 - I 3 ) . ( 6 ) ##EQU00004##
[0093] In the embodiments, since one .omega. is obtained through
calculation according to I.sub.1, I.sub.2, I.sub.3, and I.sub.4
recorded by the four photosensitive elements corresponding to the
repeating unit, a resolution of the photosensitive camera is
actually changed to a quarter of its own resolution.
[0094] It will be noted that, all the .omega. (i.e., each repeating
unit corresponding to one .omega.) obtained through calculation may
be stored as matrix data. Since all the repeating units are
actually arranged in a matrix, an arrangement of all the .omega.
may be the same as an arrangement of all the repeating units. For
example, as for a repeating unit in a first row and in a first
column, one .omega. is obtained through calculation according to
I.sub.1, I.sub.2, I.sub.3, and I.sub.4 recorded by four
photosensitive elements corresponding to the repeating unit, and
the .omega. may also be in a first row and in a first column in a
matrix. As for a repeating unit in a first row and a second column,
one .omega. is obtained through calculation according to I.sub.1,
I.sub.2, I.sub.3, and I.sub.4 recorded by four photosensitive
elements corresponding to the repeating unit, and the .omega. may
also be in the first row and in a second column in the matrix. As
for a repeating unit in a p-th row and in a q-th column, one
.omega. is obtained through calculation according to I.sub.1,
I.sub.2, I.sub.3, and I.sub.4 recorded by four photosensitive
elements corresponding to the repeating unit, and the .omega. may
also be in a p-th row and a q-th column in the matrix. In this way,
phase information of N rows and M columns may be obtained. p, q, N,
and M are all positive integers, p is less than or equal to N, and
q is less than or equal to M.
[0095] On this basis, in some embodiments, the step of calculating
the amount of strain of the object to be measured according to the
change between the phase information before the object to be
measured is deformed and the phase information after the object to
be measured is deformed includes:
[0096] obtaining phase information .omega..sub.2(i, j) of object
light received by respective photosensitive elements corresponding
to respective micro-polarizers in the repeating unit that is in an
i-th row and in a j-th column before the object to be measured is
deformed, and phase information .omega..sub.1(i, j) of object light
received by the respective photosensitive elements corresponding to
the respective micro-polarizers in the repeating unit that is in
the i-th row and in the j-th column after the object to be measured
is deformed;
[0097] calculating an amount of strain in an x direction of the
surface of the object to be measured that is photographed by the
respective photosensitive elements corresponding to the respective
micro-polarizers in the repeating unit that is in the i-th row and
in the j-th column according to a following formula (7),
.omega..sub.1(i, j) and .omega..sub.2(i, j):
x = .omega. 1 ( i , j ) - .omega. 2 ( i , j ) .DELTA. x ; ( 7 )
##EQU00005##
and
[0098] calculating an amount of strain in a y direction of the
surface of the object to be measured that is photographed by the
respective photosensitive elements corresponding to the respective
micro-polarizers in the repeating unit that is in the i-th row and
in the j-th column according to a following formula (8),
.omega..sub.1(i, j) and .omega..sub.2(i, j):
y = .omega. 1 ( i , j ) - .omega. 2 ( i , j ) .DELTA. y . ( 8 )
##EQU00006##
[0099] Where i and j are both positive integers, the x direction
and the y direction are perpendicular to each other, and .DELTA.x
and .DELTA.y are respectively actual sizes of a region of the
object to be measured corresponding to the photosensitive elements
in the x direction and in the y direction.
[0100] Whether before the object to be measured is deformed or
after the object to be measured is deformed, the .omega. obtained
are in one-to-one correspondence with the repeating units.
Therefore, as for each repeating unit, after a difference of
.omega..sub.1 corresponding to the repeating unit after the object
to be measured is deformed and .omega.2 corresponding to the
repeating unit before the object to be measured is deformed is
respectively divided by .DELTA.x and .DELTA.y, the amount of strain
in the x direction and the amount of strain in the y direction of
the surface of the object to be measured that is photographed by
all the photosensitive elements corresponding to the repeating unit
may be obtained. Therefore, through calculation from formulas and
relational expressions (1) to (8), the amount of strain of the
object to be measured may be accurately calculated.
[0101] It will be noted that, the x direction and the y direction
are any two directions perpendicular to each other in an imaging
plane when the corresponding photosensitive elements take a
photograph of the object to be measured. .DELTA.x and .DELTA.y may
be obtained in advance by using a related method, and .DELTA.x and
.DELTA.y are known values. For example, .DELTA.x and .DELTA.y may
be obtained by using a calibration method.
[0102] By using the method for measuring the amount of strain of
the object, the amount of strain of the object to be measured may
be measured in real time or periodically. The phase information
before the object to be measured is deformed needs to be measured
before the object to be measured is deformed. The phase information
before the object to be measured is deformed that is obtained may
be pre-stored in the processor or a memory for use. A method for
measuring the phase information before the object to be measured is
deformed may be the method in some embodiments of the present
disclosure.
[0103] Those skilled in the art will appreciate that, the algorithm
steps in the examples described in the embodiments disclosed herein
may be implemented by using electronic hardware, computer software,
or a combination thereof. In order to clearly describe that the
hardware and the software are interchangeable, composition and
steps of each example have been described generally in terms of
functions in the above description. Whether these functions are
implemented by using the hardware or the software depends on
specific applications and design constraints of the technical
solution. Those skilled in the art may use different methods to
implement the described functions for each specific application.
However, such implementation should not be considered to exceed the
scope of the present disclosure.
[0104] For example, the method described in some embodiments of the
present disclosure may be implemented by executing software
instructions. The software instructions may be composed of
corresponding software modules, which may be stored in a random
access memory (RAM), a flash memory, a read only memory (ROM), an
erasable programmable ROM (EPROM), an electrically EPROM (EEPROM),
a register, a hard disk, a mobile hard disk, a compact disc read
only memory (CD-ROM) or a storage medium in any other form known in
the art.
[0105] Therefore, some embodiments of the present disclosure
provide a non-transitory computer-readable storage medium storing
computer program instructions configured to perform one or more
steps of the above method for measuring the amount of strain of the
object, so as to measure the amount of strain the object to be
measured.
[0106] Some embodiments of the present disclosure provide a
computer program product. The computer program product includes
instructions that, when run on a computer, cause the computer to
perform one or more steps of the method for measuring the amount of
strain of the object according to some embodiments of the present
disclosure to measure the amount of strain of the object to be
measured.
[0107] Those skilled in the art will appreciate that, in one or
more examples described above, functions described herein may be
implemented by using hardware, software, firmware or any
combination thereof. In a case where the functions are implemented
by using the software, the functions may be stored in the
non-transitory computer-readable storage medium or may be
transmitted as one or more instructions or codes in the
non-transitory computer-readable storage medium. The non-transitory
computer-readable storage medium includes a computer storage medium
or a communication medium. The communication medium includes any
medium that facilitates transmission of a computer program from one
place to another. The storage medium may be any available medium
that may be accessed by a general-purpose computer or a
special-purpose computer.
[0108] Some embodiments of the present disclosure provide an
electronic device including a processor and a memory. The memory
stores computer program instructions suitable for being executed by
the processor. When the computer program instructions are run by
the processor, the processor performs one or more steps in the
above method for measuring the amount of strain of the object to
measure the amount of strain of the object to be measured.
[0109] The processor is used to support the electronic device to
perform one or more steps in the above method for measuring the
amount of strain of the object, and/or is used for other processes
for the techniques described herein. The processor may be a central
processing unit (CPU), or any other general-purpose processor, or a
digital signal processor (DSP), an application specific integrated
circuit (ASIC), a field programmable gate array (FPGA), or any
other programmable logic device, a discrete component gate circuit
or a transistor logic device, a discrete hardware component, or the
like. The general-purpose processor may be a micro-processor, or
any conventional processor.
[0110] The memory is used to store program codes and data of the
electronic device provided by some embodiments of the present
disclosure. The processor may perform various functions of the
electronic device by running or executing software programs stored
in the memory, and calling the data stored in the memory.
[0111] The memory may be, but is not limited to, a read-only memory
(ROM) or a static storage device of any other type that can store
static information and instructions, a random access memory (RAM),
or a dynamic storage device of any other type that can store
information and instructions, or an electrically erasable
programmable read-only memory (EEPROM), a compact disc read-only
memory (CD-ROM) or any other disc, a compact disc (including a
compact disc, a laser disc, an optical disc, a digital
general-purpose disc, and a Blu-ray disc), a magnetic disk storage
medium or any other magnetic disk storage device, or any other
medium that can be used to carry or store desired program codes
with instructions or data and can be accessed by a computer. The
memory may exist independently and be connected to the processor
through a communication bus. The memory may also be integrated with
the processor.
[0112] The foregoing descriptions are merely specific
implementation manners of the present disclosure, but the
protection scope of the present disclosure is not limited thereto.
The protection scope of the present disclosure shall be subject to
the protection scope of the claims.
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